巨厚火成岩下注浆充填载荷传递规律研究

发布时间：2018-06-28 15:54

本文选题：巨厚岩层 + 注浆充填　；参考：《中国矿业大学》2017年硕士论文

【摘要】：巨厚岩层作为一种特殊覆岩结构,在开采其下方煤层时常常导致动力现象发生,严重影响安全生产。巨厚岩层悬空不断导致的煤体应力集中,是此类灾害发生的重要原因。利用地面钻孔对巨厚岩层下部的离层区进行注浆充填,通过充填体将岩层载荷向下传递至采空区,从而有效支撑巨厚岩层,是降低该岩体悬空引起应力集中的有效手段。在该方法的实施中,注浆充填参数对覆岩载荷传递特性以及煤层采动应力转移的影响是影响工程效果的关键。因此,论文以数值模拟实验为主要研究手段,研究了巨厚火成岩下注浆充填载荷传递规律,并通过工程实践进行验证。研究揭示了注采比、注浆充填层位等关键充填参数对巨厚火成岩下采动应力转移的影响特征。由于充填体对覆岩载荷的下向传递作用,巨厚火成岩下离层注浆充填后将改变采动应力分布特征,集中表现在采空区承载力得到增加、实体煤应力集中得到减缓,其中,影响载荷传递性的工艺参数是注采比与充填层位。研究发现,控制载荷传递性的关键因素是注采比(即充填量),与其相比,充填层位对载荷传递的影响要小很多。注采比越大,巨厚火成岩下采煤时采动应力集中程度越小;随着注采比的增加,采空区的应力峰值明显增加,煤体侧应力峰值、集中系数明显降低,应力影响范围减小;在注采比为50%时,应力集中增量降幅可达20%。在注采比相同条件下,注浆充填层位越高,煤体侧应力集中越小,注浆充填载荷传递效果越好。因此,巨厚火成岩下实施注浆充填时,在保证充填量的前提下,可优先考虑选择其底界面作为充填层位。研究得出了采空区支撑率与充填参数之间的关系。采空区支撑率随注采比的增加而增加,随着注浆充填层位的升高逐渐降低。在采宽150m条件下,注采比为32%~65%时,采空区支撑率为13%~39%;在相同注采比时,随着采宽加大,支撑率还会明显加大。注浆充填层位在煤层上方70m~170m时,采空区支撑率为46%~39%;在相同注浆充填层位时,支撑率随采宽增加有降低趋势。同时,研究得出,采空区支撑区范围与煤体采动应力特征参数均呈负相关,即采空区支撑带范围不断增大时,煤体侧应力集中系数、应力集中增量、采动应力影响范围不断减小。在海孜煤矿Ⅱ1026工作面实施巨厚火成岩下隔离注浆充填减灾试验,有效降低了采动应力集中造成的动力灾害,未出现因巨厚火成岩导致的采动灾害,安全采出原煤56.3万吨,达到了安全回采的目的。
[Abstract]:As a special overlying rock structure, the huge thick rock stratum often leads to the occurrence of dynamic phenomenon and seriously affects the safety production when mining the coal seam below it. It is an important cause of this kind of disaster. It is the important cause of this kind of disaster. In the implementation of this method, the effect of grouting filling parameters on the load transfer characteristics of overburden and the effect of the coal seam mining stress transfer is the key to the effect of the shadow engineering. Therefore, the paper uses the numerical model in the implementation of the method. As the main research method, the law of loading transfer of grouting filling under huge thick igneous rock is studied and verified by engineering practice. The study reveals the influence of key filling parameters, such as injection production ratio, grouting filling layer and other key filling parameters on the mining stress and transfer under huge thick igneous rock. After the thick igneous rock grouting, the distribution of the stress distribution will be changed, the bearing capacity in the goaf is increased, the stress concentration of the solid coal is slowed down, and the process parameters affecting the load transfer are the injection production ratio and the filling layer. Compared with it, the effect of filling layer on load transfer is much smaller. The greater the injection production ratio, the smaller the concentration of the stress concentration in the coal mining under the huge thick igneous rock; with the increase of injection production ratio, the peak stress of the goaf is obviously increased, the peak stress of the coal body, the concentration coefficient decrease obviously, the stress influence range decreases, and the stress in the injection production ratio is 50%. Under the same injection and production ratio, the higher the injection and production ratio, the higher the grouting and filling layer, the smaller the stress concentration in the side of the coal body, the better the effect of the filling load transfer. Therefore, the bottom interface can be selected as the filling layer on the premise of ensuring the filling amount under the premise of filling the Thick Igneous Rock under the condition of grouting filling, and the goaf is studied. The relationship between the support rate and the filling parameters. The support rate of the goaf increases with the increase of injection production ratio, and gradually decreases with the increase of grouting filling level. Under the condition of 150m width, the supporting rate of the goaf is 13%~39%, when the injection production ratio is 32%~65%, the support rate will obviously increase with the same injection production ratio. When the position is above the coal seam, the support rate of the goaf is 46%~39%, while the support rate increases with the mining width at the same grouting layer. At the same time, it is concluded that the support area of the goaf is negatively correlated with the coal mining stress characteristic parameters, that is, the stress concentration coefficient of the coal body side should be increased when the range of the support zone is increasing in the goaf. The force concentration increment and the influence range of the mining stress are decreasing continuously. In the second 1026 working face of Haizi coal mine, the isolation grouting and filling reduction test under the thick igneous rock is carried out, which effectively reduces the dynamic disaster caused by the concentration of the mining stress concentration, and has not produced the mining disaster caused by the huge thick igneous rock, and the safe recovery is achieved by the safety recovery. Yes.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD823.7

【参考文献】